Recommend Products
Name: Fujian Monel 400 Double End Stud Material: Monel 400 Standard: ASME B18.2.1 Size: 5/16 to 4 inch Length: 30 to 1000 mm Class: 12.9 Feature: Resistant to hydrofluoric acidQS Fastener: Monel 400 Double End Stud
Name: Inconel 625 Double End Stud Material: Inconel 625 Standard: ASME B18.2.1 Size: 5/16 to 4 inch Length: 30 to 1000 mm Class: 12.9 Feature: High Yield Strength, Durable Strength and Corrosion ResistanceQS Fastener: Inconel 625 Double End Stud
Name: Xiamen Inconel 600 High Strength Fastener Material: Inconel 600 Standard: ASME Size: 5/16 to 4 inch Length: 30 to 1000 mm Class: 12.9 Feature: High Yield Strength, Durable Strength and Corrosion ResistanceQS Fastener: Inconel 600 High Strength Fastener
Name: Inconel 600 Stud Bolt Putian Material: Inconel 600 Standard: ASME B18.2.1 Size: 5/16 to 4 inch Length: 30 to 1000 mm Class: 12.9 Feature: High Yield Strength, Durable Strength and Corrosion ResistanceQS Fastener: Inconel 600 Stud Bolt
Monel K500 Hex Head Bolt
QS Fastener: Monel K500 Hex Head Bolt
Name: Monel K500 Hex Head Bolt
Material: Monel K500, UNS N05500/2.4375
Hardness: 140 to 315 HB
Size: M30
Length: 50 mm
Application: For strong acid, strong alkali and high temperature, high pressure
Feature: nonmagnetic, high strength, corrosion resistance
Material: Monel K500, UNS N05500/2.4375
Hardness: 140 to 315 HB
Size: M30
Length: 50 mm
Application: For strong acid, strong alkali and high temperature, high pressure
Feature: nonmagnetic, high strength, corrosion resistance
Quantity
Monel K500 Hex Head Bolt is manufactured from a special nickel-copper alloy, with specifications such as M30×50mm and hardness ranging 140-315HB. Combining non-magnetic properties, ultra-high strength, and exceptional corrosion resistance, it is specifically designed for extreme environments involving strong acids/alkalis, high temperature, and high pressure. As a premium fastener, it is the preferred choice for critical equipment in petrochemical, seawater desalination, and nuclear industries.
1. High-Temperature Oxidation Mechanism of Monel K500 Hex Head Bolt
The high-temperature resistance of Monel K500 Hex Head Bolt stems from the synergistic effect of its Ni-Cu matrix and γ' (Ni₃(Al,Ti)) precipitates. However, at temperatures exceeding 480°C, performance degradation occurs due to:
- γ' Phase Coarsening: Ni₃(Al,Ti) particles agglomerate and grow, reducing precipitation strengthening.
- Oxide Layer Evolution: A NiO-dominant oxide film forms, but Cu migration causes localized oxide film fracture.
The high-temperature resistance of Monel K500 Hex Head Bolt stems from the synergistic effect of its Ni-Cu matrix and γ' (Ni₃(Al,Ti)) precipitates. However, at temperatures exceeding 480°C, performance degradation occurs due to:
- γ' Phase Coarsening: Ni₃(Al,Ti) particles agglomerate and grow, reducing precipitation strengthening.
- Oxide Layer Evolution: A NiO-dominant oxide film forms, but Cu migration causes localized oxide film fracture.
2. Temperature-Dependent Performance Data of Monel K500 Hex Head Bolt
| Temperature Range | Mechanical Property Changes | Oxidation Rate | Microstructural Evolution |
| -200°C to 200°C | Strength retention >95%, no impact toughness loss (ASTM E23 cryogenic impact test) | Negligible (stable oxide film) | No γ' coarsening; dislocation motion restricted |
| 200°C to 480°C | Tensile strength reduction ≤10% (aged: 1200MPa → 1080MPa @480°C/1000h) | 0.002–0.005 mm/year (ASTM G54) | γ' growth <20nm (TEM observation) |
| 480°C to 600°C | Tensile strength drops 30–40% (1200MPa → 720MPa @600°C/100h) | 0.01–0.03 mm/year (oxide spalling) | γ' size >50nm; Cu segregation at grain boundaries (EDS) |
| >600°C (short-term) | Instantaneous strength maintained (e.g., Rm ≥850MPa @600°C/1h), but creep life <100h @650°C/200MPa | Rapid oxidation (>0.05 mm/year) | γ' dissolution; Ni-Cu-Al-Ti eutectic formation (SEM) |
3. High-Temperature Oxidation Kinetics of Monel K500 Hex Head Bolt
- Oxidation Weight Gain (ASTM G76):
- 480°C/1000h: 0.8–1.2 mg/cm² (dense NiO + minor Cu₂O).
- 600°C/100h: 3.5–5.0 mg/cm² (stratified oxide film: inner NiO, outer CuO-rich).
- Oxidation Weight Gain (ASTM G76):
- 480°C/1000h: 0.8–1.2 mg/cm² (dense NiO + minor Cu₂O).
- 600°C/100h: 3.5–5.0 mg/cm² (stratified oxide film: inner NiO, outer CuO-rich).
- Oxide Composition (XPS Analysis):
- <400°C: >90% NiO + trace Al₂O₃ (protective).
- >480°C: 70% NiO + 25% CuO + 5% TiO₂ (CuO increases brittleness).
- <400°C: >90% NiO + trace Al₂O₃ (protective).
- >480°C: 70% NiO + 25% CuO + 5% TiO₂ (CuO increases brittleness).
4. High-Temperature Performance Comparison of Monel K500 Hex Head Bolt vs. Competitors
| Material | Long-Term Service Limit | 600°C Tensile Strength Retention | Oxidation Rate @600°C (mm/year) |
| Monel K500 Hex Head Bolt | 480°C | 60–65% | 0.03–0.05 |
| Inconel 718 | 700°C | 85–90% | 0.01–0.02 |
| 316 Stainless Steel | 400°C | 40–50% | 0.10–0.15 |
Key Takeaways:
- Inconel 718 outperforms Monel K500 Hex Head Bolt at higher temperatures due to γ'' (Ni₃Nb) phase stability (enhanced by Nb/Mo).
- Monel K500 Hex Head Bolt offers superior cost-performance in 400–480°C ranges, especially where corrosion resistance + moderate heat resistance are required.
- Inconel 718 outperforms Monel K500 Hex Head Bolt at higher temperatures due to γ'' (Ni₃Nb) phase stability (enhanced by Nb/Mo).
- Monel K500 Hex Head Bolt offers superior cost-performance in 400–480°C ranges, especially where corrosion resistance + moderate heat resistance are required.
5. High-Temperature Service Recommendations for Monel K500 Hex Head Bolt
(1) Temperature Control
- Continuous Use: ≤450°C (strength retention >90%).
- Short-Term Peak: ≤600°C for <50h (prevents irreversible γ' coarsening).
(1) Temperature Control
- Continuous Use: ≤450°C (strength retention >90%).
- Short-Term Peak: ≤600°C for <50h (prevents irreversible γ' coarsening).
(2) Environmental Suitability
- Sulfur-Containing Atmospheres: >300°C may cause sulfidation corrosion (Ni₃S₂ formation; embrittlement threshold: 280°C).
- Oxidizing-Reducing Cycling: Aluminized coating recommended (extends oxidation resistance to 800°C).
- Sulfur-Containing Atmospheres: >300°C may cause sulfidation corrosion (Ni₃S₂ formation; embrittlement threshold: 280°C).
- Oxidizing-Reducing Cycling: Aluminized coating recommended (extends oxidation resistance to 800°C).
6. Conclusion
The 480°C long-term service limit of Monel K500 Hex Head Bolt is determined by γ' phase stability and oxide film protection. While it ranks among the top high-temperature nickel-copper alloys, prolonged load-bearing above 500°C must be avoided. For higher-temperature applications (e.g., jet engines), Inconel 718 or Waspaloy (Nb/Ti-strengthened alloys) are preferable alternatives.
The 480°C long-term service limit of Monel K500 Hex Head Bolt is determined by γ' phase stability and oxide film protection. While it ranks among the top high-temperature nickel-copper alloys, prolonged load-bearing above 500°C must be avoided. For higher-temperature applications (e.g., jet engines), Inconel 718 or Waspaloy (Nb/Ti-strengthened alloys) are preferable alternatives.
Send Message
